TWIS multiple salve address

RE: TWIS multiple salve address

jatfc — Tue, 25 Jul 2023 14:27:21 GMT

In the newer framework, you should be able to simply invoke the check of MATCH (via hal/nrf_twis.h) from the callback handler:

fc_uint08_t ub_Idx = nrf_twis_match_get(m_twis.p_reg);

Which will give the address register index. If you want the address you'd have to use that to select it; but for buffering the index is better.

RE: TWIS multiple salve address

mrono — Tue, 06 Nov 2018 13:05:56 GMT

Ok, the driver has a function to check which address matched, but the twis state machine doesn't use it. Let alone forward this information to the callback handler.

RE: TWIS multiple salve address

mrono — Tue, 06 Nov 2018 12:57:56 GMT

At least in the nRF52840 the TWIS peripheral does have two ADDRESS registers. And there is a MATCH register that indicates which of the addresses matched.

You'd think that the SDK would provide a way to use this feature, but I don't see anything in the nrfx_twis driver that would read the MATCH register. So I think this feature is simply missing from the driver.

RE: TWIS multiple salve address

awneil — Tue, 06 Nov 2018 12:17:27 GMT

fletort - Why do you want 2 Slave addresses?

A more usual approach is for the Slave to define its "internal" addressing within the message.

This is also illustrated in the thread I linked earlier.

RE: TWIS multiple salve address

awneil — Tue, 06 Nov 2018 12:14:18 GMT

[quote userid="14528" url="~/f/nordic-q-a/39881/twis-multiple-salve-address/156142"]In I2C addresses are only assigned to slave devices.[/quote]

There's nothing, in principle, to stop a Slave responding to multiple addresses.

For example, this recent thread uses an ST LSM303DLHC - which is a gyroscope and accelerometer. It has separate Slave addresses for the gyroscope function, and the accelerometer function - even thought they are physically in the same device!

When a Slave does have multiple addresses, then it seems obvious that it would need to know which address is currently being "called" ...

RE: TWIS multiple salve address

fletort — Tue, 06 Nov 2018 12:04:12 GMT

I am not talking about the master adresses. But out nrf Slave device can be reachable on 2 adresses. Is it possible to know on which adresses (on these 2) our slave device is currently adresses ?

RE: TWIS multiple salve address

Michal — Tue, 06 Nov 2018 11:59:24 GMT

In I2C addresses are only assigned to slave devices. I dont think there is a standard way to distinguish data coming from different master devices.

RE: TWIS multiple salve address

fletort — Tue, 06 Nov 2018 10:52:18 GMT

I am slave adresse, as indicated in the title. So i receive the nrfx_twis_evt_t event. But when nerf is slave it is possible for it to listen on two adresses. I would like to know if it is possible to know on which adresses the incoming request is.

RE: TWIS multiple salve address

Michal — Tue, 06 Nov 2018 10:38:27 GMT

twiS stands Slave device. If you are slave then you have your assigned address which you should be aware of. If you are implementing master with nrf you should use twi (with no s) driver. So it looks like you are using wrong driver, so I guess you didnt make it working at all on other sdks ?

RE: TWIS multiple salve address

fletort — Mon, 05 Nov 2018 16:54:24 GMT

in fact in SDK15 too, i can't this parameter. The event received is the nrfx_twis_evt_t not the nrfx_twi_evt_t that you mention

RE: TWIS multiple salve address

fletort — Mon, 05 Nov 2018 16:38:14 GMT

It this also available on the old SDK 11 ? I can't find the same parameter in this structure on this version.

RE: TWIS multiple salve address

fletort — Fri, 26 Oct 2018 13:09:46 GMT

THanks, it was for what i was looking for, but did not find it !

Thanks Again.

RE: TWIS multiple salve address

Michal — Fri, 26 Oct 2018 11:25:51 GMT

Hello,

I am not sure which SDK you are using but eg sdk 15: the event handler function type has parameter structure nrf_drv_twi_evt_t which has nrf_drv_twi_xfer_desc_t which has uint8_t field for slave address. So to print address of device related to event you can instert this snippet to your event handler function:

NRF_LOG_INFO("Device addres:%d.", p_event->xfer_desc.address);

Regards